Engineering and Physical Sciences 9:00 am Saturday, April 6, 2002 Battelle Hall 212 Miles K. Free III-Presiding.
The composition of the surface of particles is essential to the performance of surface reactive catalysts. The purpose of this research is to develop a technique to quantitatively analyze such compositions. The work to date has been in the analyses of metal oxide powders. The technique employed to analyze the surfaces was aqueous stripping. In this technique, layers of the particles are dissolved while the concentration of the stirred solution is monitored over time. Atomic Absorption Spectroscopy, with both flame and graphite furnace, was the method selected to monitor these changing concentrations. The flame atomization method used a microboat to limit the sample size. The elemental analysis of the solution indicates the composition of the layers. The data from this work is then fitted to a model that describes the concentration increase due to the dissolution of powders. In this work, optimum parameters have been obtained for both flame and the graphite furnace by successive improvements. Data fitting the proposed model has been repeated twice. In both of these instances, an unexplained concentration drop occurred approximately fifteen minutes into the dissolution process. Reproducibility has been a problem due to suspended particles being introduced to the instrument with the solution. Altering such parameters, as the acidic concentration of the dissolving solution, the stirring speed, and the dryness of the initial powder has not improved this problem. Future work to improve this situation will use microporous polypropylene membrane filters to remove the "smaller" particles and a sifter to isolate "larger" particles to be dissolved. By preventing particle introduction, the nature of the concentration drop can be investigated. Once explained, the composition of the surface of the particle could be quantified using the proposed model of dissolution.
9:15 INVESTIGATION OF METAL-ORGANIC FRAMEWORKS AS POTENTIAL HETEROGENEOUS CATALYSTS. Ana O. Ramirez, firstname.lastname@example.org (Paul S. Szalay, email@example.com) Muskingum College, 163 Stormont St, New Concord OH 43762.
Traditional solid-state syntheses require the use of high temperatures and associated techniques that are very different from those conventionally used in molecular studies. This limitation is largely due to the fact that molecules can generally be manipulated sequentially one step at a time; whereas solids are often assembled in a single step. A high level of synthetic control over the structure and properties of novel extended solid systems has rarely been possible. A new synthetic method involving the precipitation of new materials by mixing solutions of soluble precursor complexes has recently been demonstrated to address this limitation. Aspects of the advantages over the old methods are discussed. Extended systems prepared this way have been found to exhibit desirable properties such as robust framework stability, microporosity, and guest-exchange. The design and preparation of metal-organic frameworks, that are assembled by linking together metal ions with organic molecules is investigated. Our attention is focused on organic ligands with three coordinate donor sites such as hexaazatriphenylene-hexacarboxamide (HAT-[(CON[H.sub.2]).sub.6]), and hexaazatriphenylenecarboxilic acid (HAT-[(C[O.sub.2]H).sub.6]).These ligands possess desirable structural and electronic features that are well suited to coordinating to transition metals. The metals that we will explore include [Ti.sup.IV] and [Zr.sup.IV]. This is in an attempt to obtain frameworks that have potential to serve as heterogeneous catalysts.
9:30 THE RATIO OF F: Sn AND ITS IMPORTANCE IN THE TRANSPARENT CONDUCTING OXIDE Sn[O.sub.2]: F. Nari N. Talaty,
nari firstname.lastname@example.org Dean M. Giolando, Dept of Chemistry, University of Toledo, Toledo OH 43606-3390.
Tin oxide doped with fluoride is an important and widely studied transparent conducting oxide (TCO) due to its properties and its commercial uses. It has the longest plasma wavelength, best ohmic contact to p-Si, highest thermal stability; it is the hardest and has the lowest cost. Much information is available about the characterization and properties, but the actual stoichiometry of Sn or F present within the crystallites has not been calculated in greater detail. Ratios of F:Sn are based on the relative amounts added to the reactant stream. We employ known standard procedures to determine the actual composition of the thin film. We have studied Tech -15 (Libbey Owens Ford, Pilkington) films having a resistance of about 15 ohms and thickness of Sn[O.sub.2] layer of 250 nm. Etching of the film was carried out using zinc powder and HCl (3N trace metal grade) and by electrochemical methods using a platinum and a carbon electrode. After successfully etching the surface, by wet chemical and electrochemical methods, analysis for Sn and F were carried out. The tin content was determined using Inductively Coupled Plasma Spectroscopy (ICP), Anodic Stripping Voltammetry and D.C. Polarography. The Fluoride ion concentration was determined using an Orion 9609 [F.sup.-] Ion Selective Electrode and also via Colorimetry (Alizarin Red). Primary results using ICP yielded a Sn concentration (0.1 to 0.3 ppm) at 186 nm excitation. The fluoride concentration was measured at the ppb levels by using suitable buffers (TISAB II, TISAB II, Glycine:HCl). The measured values are in good agreement with the calculated values. The importance of obtaining the F:Sn ratio is based on the fact that while the carrier concentration increases with the F concentration, it decreases with excess F concentration. Hence, the optimum F concentration still needs to be determined. We can control this parameter (F concentration) during the deposition experiment. Further studies of Tech-8 (650 nm, 8 ohms resistance) and ZnO: F films (1 ohm resistance) are considered.
9:45 PUNCTUATED EQUILIBRIUM AND THE SCREW MACHINE PRODUCTS INDUSTRY. Miles K. Free III, email@example.com 350 Woodland Dr., Medina OH 44256.
A gradualist business model of incremental change has been widely accepted as the predominate model for the screw machine parts manufacturing industry. The "Punctuated Equilibrium Model" first proposed by Steven Jay Gould and Niles Eldridge in 1972 offers an alternative model for viewing this industry plus the challenges and the rate of change it currently faces. Parts per million quality requirements, difficult to achieve using standard statistical methods; industry wide closures of customary suppliers; reverse auction sites and customer retrenchment are examples of the cataclysmic events that are driving the evolution of this industry, indicating the need for a new non gradualist model. Organizational competencies necessary for success in a Punctuated Equilibrium Environment include application of statistics plus data mining techniques to facilitate estimation and costing. Process path documentation and failure mode effects analysis planning to assure raw materials are obtained that are optimized for the application. Error proofing and process improvement techniques to improve process, product, and service quality are also essential to drive organizational performance to 0 PPM levels.
10:00 APPLICATION OF AGILITY PRINCIPLES TO MANUFACTURING INDUSTRIES -- THE ASSESSMENT METHODOLOGY, Bahman Ghorashi, b.Ghorashi@csuohio.edu and Nitin Das, Dept of Chemical Engineering, Cleveland State University, Cleveland OH 44115, and Anne M. Ghorashi, AGA Gas Inc: A study was initiated to identify the strategic needs of the adhesive manufacturing sector of the chemical industry in relation to agility principles. An agile company can be defined as an enterprise that is capable of operating profitably in a competitive environment of continually, and unpredictably, changing customer opportunities . In this paper, the authors describe and discuss the methodology that was utilized to assess the agility of three companies that participated in this study. These companies were studied and observations were made with respect to the answers that were provided by these three companies as well as an in-depth analysis of the survey results. In determining the degree of agility of the three selected companies, an assessment questionnaire was prepared. Selected company personnel answered the questionnaire. Separate analyses of the responses were then made for each company. In this paper, we describe the main segments of the questionnaire and the assessment methodology, followed by a discussion of our findings. The analyses of our results revealed that none of the three companies would fully satisfy the different agility criteria that we had outlined. The overall analyses revealed that the three adhesive manufacturing companies seem to, more or less, follow the same trend with respect to their individual operations and showed certain weaknesses in their operations, which we identified.
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|Publication:||The Ohio Journal of Science|
|Date:||Mar 1, 2002|
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